Window heater



Jan. 13, 1959 M. e. STEELE 2,868,943

WINDOW HEATER Filed Dec. 6, 1955 2 Sheets-Sheet 1 Fig.1.

IN VEN TOR. MAURICE 6. 675615 A 7" TUBA/EX M. G. STEELE WINDOW HEATER Jan. 13, 1959 2 Sheets-Sheet 2 Filed Dec. 6, 1955 INVENTOR. mun/c5 a STEELE ATTORMFX United States Pa r WINDOW HEATER Maurice G. Steele, Rome, N. Y.

Application December 6, 1955, Serial No. 551,332

5 Claims. (Cl. 219-44) This invention relates to heaters, and more particularly to an electrically operated heater which is adapted to be applied to a window for counteracting the effect of heat losses through and around the window.

During cold weather, windows having an outdoor exposure are generally a source of discomfort to persons near them indoors. This condition is due partly to the fact that a down draft of cold air occurs at the inner surface of the window, partly to the leakage of air around the edges of the sash especially on windy days, and partly to the rapid radiation of heat outwardly through the window. It is also due to the fact that the warm bodies of occupants of the room radiate heat to the much colder window panes causing a feeling of discomfort.

While storm sashes or double window panes may serve to reduce the temperature difierential between the inner surface of the window and the air in the room, they cannot wholly eliminate this temperature differential, and moreover are of little value in preventing the substantial heat losses which are due to outward radiation through the window.

Accordingly, one object of this invention is to provide a heater having a heating element which is so arranged that it will convert a cold down draft of air adjacent the window into an upwardly directed convection air current that is substantially above room temperature.

Another object is to provide a heater of the above nature which is adapted to heat air which leaks inwardly around the sash, or which is admitted through the win dow (at the bottom) for purposes of ventilation and convert it into an upwardly directed convection air current that is substantially above room temperature.

Another object is to provide a heater having a heating element which is so arranged as to neutralize outwardlyradiated heat loss through the window by means of inwardly directed radiant heat.

Another object is to provide a heater of the above nature having a ventilator screen which may be used as a shield independently of the heating element, whereby occupants of the room may be protected against cool drafts resulting from air which may be admitted through the lower part of the Window for purposes of ventilation.

Another object is to provide a heater of the above nature which is so constructed as to substantially counteract the heat losses attributable to the window, thus eliminating personal discomfort, and is not intended to supply any large quantity of heat to the interior of the room, whereby the heater may operate effectively without overheating the room and economy of operation may be obtained.

Another object is to prevent radiation of heat from the bodies of occupants of the room to the cold window whereby personal discomfort would result.

. Another object is to heat and temper the cool or cold air which may be admitted to the room by raising the lower sash whereby fresh air may be enjoyed without discomfort.

. Another object is to prevent the condensation and f s nt vi Patented Jim. 13, 1959 to collect on windows in cold weather, thus maintaining the proper degree of humidity in the room and preventing damage to the sash and its finish.

A further object is to provide an invention of the above nature which will be simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, ornamental in appearance, and very eflicient and durable in use.

With these and other objects in view, there have been illustrated on the accompanying drawings several forms in which the invention may be conveniently embodied in practice.

in the drawings,

Fig. 1 is a perspective view showing one form of the improved Window heater, partly broken away, as it would appear when mounted in operating position with relation to a window.

Fig. 2 is a cross-sectional view of the same, with arrows added to show the direction of the air currents during operation,

Figs. 3 and 4 are cross sectional views, similar to Fig. 2 but showing the second and third forms of the window heater respectively.

Fig. 5 is a cross sectional view of a fourth form of the Window heater.

6 is a partial front view of the heater of Fig. 5.

Fig. 7 is a cross sectional view of a fifth form of the window heater.

Fig. 8 is an exploded, perspective, fragmentary view of the heater shown in Fig. 7.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral 10 indicates generally a Window heater which is adapted to be applied to a window of the type having a pane it carried in a sash i2, inner stops 13 at the inner cages of said sash, casings 14, and a stool 15.

The window heater 1% comprises a rectangular ventilator screen 15 of any suitable material, such as metal, plastic, glass, or plywood, which has a length approximately equal to the distance between the Window stops 13, and which has a pair of trapezoidal end walls 17, 18 adapted to be secured to the stops 13 by means of screws 19, whereby the screen 16 may be secured in a position which is inwardly and upwardly inclined from the stool 15.

The heater 10 also comprises a heater assembly 20 which is mounted upon the surface of the screen 16 facing the sash 7.2, and which includes an elongated horizontal heating element Zl of the electrical resistance type having an attachment cord 22 and an attachment plug 23 which is adapted to be inserted into any convenient outlet 24. The heating element 21 has a capacity which will permit it to approximately counteract the heat losses through and around the window, and it has been found that a capacity of around 200 watts per foot of window width will provide satisfactory operation during the winter season in the temperate zone.

The heater 2G also comprises rectangular inner and outer plates 25, 26 Which are parallel to and approximately the same length as the ventilator screen 16, and which are secured together in spaced relation by means of two or more screws 28 and nuts 36 Only one screw and nut are shown in Fig. 2. The heater plates are preferablyof metal havin a good coeflicient of thermal conductivity and may be provided with a dull black finish so as to enhance their heat absorption characteristics.

In order to hold the heater plates 25, 26 apart, each of the screws is provided with a pair of spacer sleeves 31, the ends of the heating element 21 being disposed between the respective pairs of spacer sleeves 31 and apertured to receive the screws 28, whereby said heating element 21 is supported midway between the heater plates aseaaae q? 25, as. in order to mount the spaced relation upon the outer side of the ventilator screen in, the inner heater plate is provided with a plurality of shouldered support studs 32, which are secured in apertures in said screen by means of nuts.

The lower edge of the inner heating plate 2 is povided with an out-turned flange 34, while the lower edge oi the outer heater plate 25 is provided with an iii-turned flange thus preventing excessive downward radiation from the heating element 21 which might otherwi 3 d age the lower rail of the sash l2 and the flange 34, 35 will also serve to provide stiirness in the heater assembly 2', thus strengthening said assembly against warping or other deformation.

It will be noted, however, that the outer plate somewhat narrower than the inner plate iii-turned flange E is dispose in oilset relat the out-turned and thus will permit a r or" air to enter freely between the lower edges of plates.

heater assembly 26 in said Second form 3 shows a second form of window heater 37, C611:- prising a rectangular ventilator screen 33 which rests in an inclined position upon the window stool l5, and which is provided with trapezoidal end walls 39 adapted to be secured to the window steps 13 by means of screws ill.

Provision is made of a heater assembly 41 which rests upon the outer surface of the ventilator screen and which comprises a rectangular inner heater plate and an outer heater plate 43. The outer plate 43 r a flanged U-shape in cross section and is secured to the outer surface of the inner heater plate 4-12 by any suitable means such as welding.

An elongated electrical resistance heating element 44 is supported midway between and parallel to the inner and outer heater plates 42, 43 by means of screws engaged through the heater plate 43 and heating element 44 and nut 46 and spacer sleeves 47 on said screws.

In order to permit a circulation of air upwardly through the space between the heater plates 42, 4-3, and past the heating element 44, the upper and lower sides of the outer heater plate 43 are perforated so as to form grillwork 4-3, 49.

The heater assembly 41 is adapted to be supported in spaced relation to the outer surface of the screen by means of a plurality of heater support pins 553 which are secured to the inner heater plate 1-2 so as to rest upon the inner surface of said ventilator screen The lower edge of the inner heater plate 42 is provided with an outwardly extending flange "ll having dependi g supporting studs 52, the lower ends of which are adapted to be engaged in angle clips 53 secured to the upper surface of the window stool 15 by screws 54.

Thus, in the second form of the invention, it will. be seen that the heater assembly 41 may be easily removed from the ventilator screen 33 and replaced therein desired, and further, that the grillwork 48, 49 will protect the heating element from obstruction by or contact with window curtains, papers or other external objects.

it will be understood, however, that the heating element 44- will operate at a relatively low temperature which will be incapable of igniting readily any inflammable material which may come in contact with it.

Third form A third form of window heater 55, which is shown in 4, comprises a lJ-shaped ventilator screen or baffle Sit; having a horizontal flange 57 which is adapted to be secured upon the edge of the window stool 15 by means of screws engaged therethrough, so that said screen 5: will be supported in 21 depending position inwardly of the stool 15.

The inner wall of the screen 56 is extended upwardly and inclined toward the window so as to provide an upper shield portion 59.

The interior of the ventilator screen 56 is provided with a heater assembly at comprising an elongated electrical resistance heater element 61 which is supported by-means of screws 62 extending through said screen and secured by nuts 63.

The screws 62 also support a pair of vertical battle plates dd, 65 at opposite sides of the heater element 6i, said bafile plates being held in spaced relationship to said heater element and to the screen 56 by means of spacer sleeves 66 on the screws 62.

in order to minimize losses of heat from the heating element 61 in the direction of the window casing, and also to guide movements of air through the ventilator screen or baflle 56, provision is made of an angular guide plate 57 which is supported in parallel relationship upon the batlle plate 64 by means of spacer rivets 68, and wiich has an inclined upper portion 67a extending outwardly above the stool 15. The angular guide plate 67 might advantageously be made of an insulating material to minimize the radiation of heat from this plate to the cool descending air on the side toward the sash.

Fourth form Figs. 5 and 6 show a fourth form of window heater 6?, n which the ventilator screen and the heating element are embodied in a single rectangular panel 7i. of glass or other suitable transparent or other material having embedded thei a plurality of loops of electrical resistance wire 7i which are adapted to be connected to a source of electric current.

Alternatively this panel 70 might be made of so-called radiant glass with no embedded wires, the glass itself being heated due to its electrical resistance when current is applied thereto.

The panel '76 is adapted to be supported in an inclined position upon the stool 15 by means of trapezoidal brackets '72 which are adapted to be secured to the window stops l? by means of screws 73, and which have inclined parallel flanges 7d, '75, embracing end portions or said panel I'll. These flanges are suitably connected by a transverse member '76 upon which the lower horizontal edge of the panel 70 rests. This spaces the panel a small distance away from the sill 15 and prevents damage to the sill from radiated heat from the panel.

Fifth form A fifth form of window heater 77, which is shown in Figs. 7 and 8, comprises a vertical heater support 78, which also serves as an air bafile, having a horizontal Flanged portion 86 which is adapted to rest upon the stool r5 supporting the heater assembly in a position approximately parallel to the window pane 11 as shown in Fig. 7.

Fastcned to the heater support 78 by means of horizontal bolts 79 and nuts Sit are several components which comprise the complete heater assembly as shown in the exploded perspective view of Fig. 8. The bolts 79 pass through holes 91 in each component, drawing them snugly together.

A rectangular metal heater plate 9!), which is equal in length to the heater support 73, extends horizontally as shown. To it is welded a plurality of vertically disposed tlanged metal heater fins 32 which provide an extended heating surracev The fins 82 are welded to the plate 9%"; at flanged portions 93.

The heater plate 9% also has vertical and horizontal flanges $2 at its edges forming in eifect an open box. An outer heater plate 81, having horizontal flanges is held by the bolts 79, and engages the fins S2 at their free edges giving strength, rigidity and a finished appearance thereto, and also provides a baffle plate for the passage of heated air upwardly between the fins 82.

A heater element. 84- is of the electric resistance type comprising a thin rectangular matrix or mat of insulating material to which a flat grid of resistance wire has been stapled. On either side of this element 34 a pair of relatively thin rectangular sheets 85 of suitable insulating material are placed to insulate the resistance wire from the adjacent metal parts.

Between the heater support 78 and the adjacent sheet of insulating material 85 is a rectangular pad 83 of thermally insulating material which is fireproof. The elements 83, 84 and 85 fit snugly into the open box portion of the heater fin plate 90 which houses them.

The heater support 78 has horizontal and vertical flanges 87 and 89 which fit around the flanges of the heater fin plate 90 completely enclosing the elements 83, 84 and 85.

Because of its proximity to the heater fin plate 90 in the assembled unit, the heat from the heater element 84 is readily transmitted to the heater fins 82 which in turn heats the air passing upwardly between them.

Operation In using the first form of the invention (Figs. 1 and 2), the heating element 21 will be energized, thus heating the air surrounding it and causing an updraft between the heater plates 25, 26. The heating element 21 will also heat said plates 25, 26 by radiation, so as to produce rising convection currents of moderately heated air between the outer plate 26 and the window pane 11, but adjacent to plate 26, and also between the inner heater plate 25 and the ventilator screen 16. Thus a downdraft of cold air descending adjacent the window pane will be converted into an updraft of warm air issuing from the top of the heater 10.

Further, the radiant heating effect of the heating element 21 will be suflicient not only to heat the heater plates 25, 26, but also to warm the ventilator screen 16, which will then radiate heat into the room in an amount suflicient to substantially counteract the loss of radiation through the window pane 11.

The flanges 34, 35 of the heater plates 25, 2.6 will prevent excessive downward radiation from the heating element 21, thus preventing damage to the window sash 12 and the stool 15 or to the finish thereon. However, sufiicient downward radiation will occur to raise the temperature slightly in the vicinity of the lower rail of the sash 12, and thus cause evaporation of moisture which might otherwise collect as a result of condensation upon the window pane 11.

It will therefore be seen that the improved window heater will not only assist in maintaining comfortable temperatures in a room, but will also tend to maintain the original degree of humidity in the air of the room, inasmuch as condensation upon the window pane will not be lost but will be returned to the air in the room.

The window heaters 37 and 55, in Figs. 3 and 4, respectively, will operate in substantially the same manner as described in connection with the window heater 10, downdrafts of cold air from the window pane 11 being coverted into updrafts of warm air emanating from the upper portion of the window heater, and the respective screens 38 and 56 being heated so as to radiate heat inwardly into the room.

The window heater 55 (Fig. 4) has the advantage of offering a minimum of obstruction to the window opening. However, if the user wishes to avoid any obstruction depending from the window stool 15, he may prefer to employ the forms shown in Figs. 2 and 3.

When the window heater 69 (Figs. 5 and 6) is employed, the heating wires 71, or the thermal glass, will of course raise the temperature of the glass panel 70, so that heat will not only be radiated inwardly into the room, but will also be transferred by convection to the relatively cold air descending vertically from the window pane 17, thus creating a warm updraft of air as in the previously described forms of the invention.

The window heater 77, in Figs. 7 and 8 operates in substantially the same manner as heaters 10, 37 and 55, downdrafts of cold air from the window pane 11 being converted into updrafts of warm air which are heated i the room temperature.

'fin plate 90, and between which the air passes.

by the extended metal fins 82, attached to the heated The thermal insulating pad 83 cuts down normal radiation which would proceed into the room from the surface of heater support '78. This increases the amount of heat passing into the fins and upwardly rising air from the window and reduces the temperature of the heater support 78 so that any chance of a person burning himself is eliminated.

It will be understood that all forms of window heater erein disclosed will serve as draft deflectors in the event that the window sash 12 should be raised for the purposes of ventilation. When the respective heating elements 21, 44, 61, 71 and 84 are in operation, they, of course, temper the incoming fresh air, and this will assist in maintaining However, when said heating elements are not in operation, as for example during warm weather, the ventilator screens will serve efficiently as draft deflectors without raising the temperature of the incoming air.

While there has been disclosed in this specification several forms in which the invention may be embodied, it is to be understood that these forms are shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosures, but may be modified and embodied in various other equivalent forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. In an apparatus for heating and deflecting a stream of cold air falling from the inside surface of an outside window of a room, the combination comprising a horizontally extending upwardly and outwardly inclined panel, a window frame, a window stool, means for securing said panel to said window frame for enclosing the lower end of said window to form a substantially airtight trough, a deflecting guide plate arranged between said panel and said window, and an elongated heating element disposed in the space between said panel and said plate, whereby the cold air from the window will be heated and deflected upwardly beyond the upper end of said panel into the room, and a second guide plate between said heating element and said panel for additionally guiding said air past said heating element, the lower edges of said plates having offset inwardly extending flanges for preventing excessive downward radiation from said heating element.

2. In an apparatus for heating and deflecting a stream of cold air falling from the inside surface of an outside indow of a room, the combination comprising a horizontally extending upwardly and outwardly inclined panel, a window frame, a window stool, means for securing said panel to said window frame for enclosing the lower end of said window to form a substantially airtight trough, a deflecting guide plate arranged between said panel and said window, an elongated heating element disposed in the space between said panel and said plate, whereby the cold air from the window will be heated and deflected upwardly beyond the upper end of said panel into the room, and a second guide plate parallel to said heating element and said panel for additionally guiding said air past said heating element, said guide plates having means for detachably supporting them and said element upon the window stool.

3. In an apparatus for heating and deflecting a stream of cold air falling from the inside surface of an outside window of a room, the combination comprising a horizontally extending upwardly and outwardly inclined panel, a window frame, a window stool, means for securing said panel to said window frame for enclosing the lower end of said window to form a substantially airtight trough, a deflecting guide plate arranged between said panel and said window, an elongated heating element disposed in geese a3 the space between said panel and said plate, whereby the cold air from the window will be heated and deflected upwardly beyond the upper end of said panel into the room, and a second guide plate arranged in parallel relation between said heating element and said panel for additionally guiding said air past said heating element, heating said air, and acting as a bafiie with respect to said panel, said heater plates being provided with a grillwork above said heating element for preventing accidental contact of foreign objects with said heating element.

4. In an apparatus for heating and deflecting a stream of cold air falling from the inside surface of an outside window of a room, the combination comprising a horizontally extending upwardly and outwardly inclined panel, a window frame, a window stool, means for securing said panel to said window frame for enclosing the lower end of said window to form a substantially airtight trough, a deflecting guide plate arranged between said panel and said Window, and an elongated heating element disposed in the space between said panel and said plate, whereby the cold air from the window will be heated and deflected upwardly beyond the upper end of said panel into the room, and including a layer of insulating material ar ranged between said heating element and said panel.

5. in an apparatus for heating and deflecting a stream of cold air falling from the inside surface of an outside window of a room, the combination comprising a horizontally extending upstanding panel, a window frame, a Window stool, means for securing said panel to said window frame for enclosing the lower end of said window to form a substantially airtight trough, a deflecting guide plate arranged between said panel and said window, and an elongated heating element disposed in the space between said panel and said plate, whereby the cold air from the window will be heated and deflected upwardly beyond the upper end of said panel into the room, and wherein said plate is provided with a plurality of spaced heat radiating fins extending into the space between said plate and said heating element.

References Cited in the file of this patent UNITED STATES PATENTS 1,288,236 Shipp Dec. 17, 1918 1,517,833 Gertler Dec. 2, 1924 1,534,221 Kercher Apr. 21, 1925 1,916,355 Bennett July 4, 1933 2,606,992 MacDonald Aug. 12, 1952 FOREIGN PATENTS 263,714 Germany Sept. 6, 1913 358,633 Great Britain Oct. 15, 1931 610,778 Great Britain Oct. 20, 1948 636,887 Great Britain May 10, 1950 1,080,398 France May 26, 1954 

